John Wheeler: Sorry, but toilets do not swirl the other way in the Southern Hemisphere

FARGO — It is a commonly held notion that toilets, when flushed, all make a counter-clockwise vortex in the Northern Hemisphere and spin the opposite way south of the equator. Although this is loosely based on a scientific fact, it is wrong. Actually, it is a fact that large-scale low-pressure weather systems all rotate counter-clockwise in the Northern Hemisphere and spin the opposite way down under.

This is a byproduct of the Earth being round and spinning on an axis. However, for rotations as small as a toilet bowl flush, the forces are too weak to have an effect. Whatever you might have heard or read about toilets flushing, the direction of spin is determined by the design of the toilet and not the rotation of the Earth.



It is the same with water in a bathtub. It can be made to swirl either way with a subtle agitation of the water..